The Piano effect displays a piano keyboard effects where the keys modulate based on the beat and frequency of the sequence audio. In addition to generating the effect using xLights inbuilt capability to process sound waves , you can also use an externally created Polyphonic Transcription notes file or an external midi file.



Notes Source

Indicates what the source for generating the Piano effects is.

Options are:

Audacity Timing file, Midi file, xLights generated Polyphonic Transmission or Notes Source.

If Polyphonic transmission is selected, then a window will be displayed and there will be a pause whilst the timings are first generated.

If ‘Audacity Timing file’ is selected, you will be prompted for the location of the Audacity file.

If ‘Midi file’ is selected, you will be prompted for the location of the Midi file.

If Notes Source is selected, then a timing track source can be used (further described after the table). This is the preferred option.


Indicates how the piano keys should be displayed - ‘True Piano’ or ‘Bars’.

Start Midi Channel

The Start and End Midi channels defines the range that the Piano keys should emulate. The wider the range, the more keys are required. 64 corresponds to the ‘Middle C’ key on the Piano.

End Midi Channel

See Start Midi Channels.

Show Sharps and Flats

If selected , then the Sharp and Flat ‘Black’ keys of the piano are shown and played.

Vertical Scale

Used to adjust the height of the effect vertically i.e. lengthen or shrink the effect.

Can be adjusted via the Value Curves options.

Horizontal Offset

Controls the position of the effect horizontally i.e. can be shifted left or right.


The name and location of the polyphonic transmission label file or Midi file if one of these have been selected as the source.


If a Midi file is selected , a list of Tracks that the file contains is displayed. You can select one of them or All (in which case the tracks are merged).

Midi Start Time Adjust

If a Midi file has been selected , this attribute can be used to adjust the synchronisation of the midi file to the song being sequenced in case they are slightly off from each other.

Midi Speed Adjust

If a Midi file has been selected , this attribute can be used to adjust the tempo (increase or slow down). It is used to try to match tempos of the songs.

Set the source to timing track and select the Track from the list of Timing tracks you have generated in the sequence.

Then, expand the view so that you can see the labels of the timing track and change the labels to match the required keys. The label can be the key letter or can be the MIDI value of the key.

You can also specify multiple values in one label and accordingly multiple keys will be depressed.

You can use a value of C# to depress the C# key , C to depress the C key or multiple values such as C F A to depress three keys.

Multiple key formats are supported:

  • 1-127: midi codes

  • C4 or c#4: note and octave

  • C or C#: notes (assumed to be 4th octave)

    Keys are separated by space, comma or colons.

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